Existing location systems, such as those used in moving vehicles, typically employ Global Positioning System (GPS) receivers. These systems generally suffer from a number of limitations such as limited precision and accuracy, a requirement of unobstructed line of sight to multiple satellites in the GPS constellation, and susceptibility to jamming and denial of service. Although some of these limitations may be overcome through the use of additional technology and equipment, these approaches are typically expensive.
Inertial navigation systems may provide an alternative method for self location of a vehicle from a known starting point. These systems use accelerometers but they require calibration and tend to drift over time thus requiring periodic re-calibration which limits their accuracy and suitability for many applications.
What is needed, therefore, are improved methods and systems for autonomous self location of an object, such as a moving vehicle, with increased reliability and precision.